Connecting device for piping

Abstract

Disclosed is a connecting device for piping for connecting a pipe to another pipe or to another part for piping. The connecting device includes an adapter and a pipe nipple configured to be threadedly engaged with the adapter. The pipe nipple is fixed to an end of a pipe, and an end of another pipe is inserted into the adapter. The adapter includes a hollow adapter body, a cap coupled to the adapter body, a grip ring configured to fix the pipe introduced into the adapter body, a body-sealing member configured to provide a seal between the adapter body and the pipe, a sleeve disposed between the grip ring and the body-sealing member, and a metal sealing member configured to provide a seal between the adapter body and the pipe nipple.

What is claimed is: 
     
       1. A connecting device for piping for connecting a pipe to another pipe or to another part for piping, the connecting device comprising:
 an adapter body having a hollow structure, the adapter body comprising a cap-coupling threaded portion formed in one end thereof, a nipple-coupling threaded portion formed in an opposite end thereof, and a tapered seating portion formed therein such that a width thereof gradually decreases from the nipple-coupling threaded portion toward the cap-coupling threaded portion; 
 a cap comprising a cap through-hole formed therein to allow a pipe to pass therethrough and a cap threaded portion formed so as to correspond to the cap-coupling threaded portion to be threadedly engaged with the adapter body; 
 a body-sealing member disposed in the adapter body so as to contact an outer circumferential surface of a pipe entering the adapter body; 
 a grip ring disposed in the adapter body, the grip ring comprising a plurality of latching pieces configured to be elastically deformed by contact with an outer circumferential surface of a pipe entering the adapter body to fix the pipe to the adapter body; 
 a pipe nipple fixed to a pipe or another part for piping, the pipe nipple comprising a nipple through-hole formed therein to allow a fluid to flow therethrough, a nipple threaded portion formed so as to correspond to the nipple-coupling threaded portion to be threadedly engaged with the adapter body, and a nipple tapered portion protruding in a forward direction of the nipple threaded portion while gradually decreasing in width; and 
 a metal sealing member comprising a sealing member body provided at an outer side thereof with an outer contact surface tapered so as to closely contact the tapered seating portion and provided at an inner side thereof with an inner contact surface tapered so as to closely contact the nipple tapered portion, the metal sealing member being disposed in the adapter body to provide a seal between the adapter and the pipe nipple, 
 wherein the adapter body comprises a protruding portion formed to have a constant width between the nipple-coupling threaded portion and the tapered seating portion, 
 wherein the pipe nipple comprises a nipple cylindrical portion having a cylindrical shape and formed to have a width smaller than a width of the protruding portion between the nipple threaded portion and the nipple tapered portion, and 
 wherein the metal sealing member comprises a plurality of sealing member protrusions protruding from an edge of the sealing member body so as to be located on the protruding portion and to contact an outer surface of the nipple cylindrical portion. 
 
     
     
       2. The connecting device according to  claim 1 , further comprising:
 a sleeve comprising a hollow sleeve body having an outer surface that is capable of coming into contact with an inner surface of the adapter body, 
 wherein the sleeve is disposed between the body-sealing member and the grip ring within the adapter so as to support the body-sealing member and the grip ring. 
 
     
     
       3. The connecting device according to  claim 2 , wherein the adapter body comprises a window formed through a portion thereof to expose an interior of the adapter body to an outside, and
 wherein the sleeve is light-transmissive, and is disposed at a position at which the window is formed. 
 
     
     
       4. The connecting device according to  claim 2 , wherein the sleeve comprises a ring-shaped inner sleeve rim portion, which protrudes from one end of the sleeve body in an inward direction of the sleeve body so as to closely contact the body-sealing member. 
     
     
       5. The connecting device according to  claim 4 , wherein the grip ring is disposed such that an edge thereof is interposed between the sleeve and the cap, and
 wherein the cap is in contact at an end thereof with the grip ring to press the grip ring and the sleeve toward the body-sealing member. 
 
     
     
       6. The connecting device according to  claim 5 , wherein the grip ring comprises a plurality of connecting portions interconnecting adjacent ones of the plurality of latching pieces, and
 wherein the cap is provided at an end thereof with a seating groove in which the plurality of connecting portions is received, the seating groove being formed to surround the cap through-hole. 
 
     
     
       7. The connecting device according to  claim 1 , wherein the latching pieces are disposed around a pipe introduced into the adapter body so as to be inclined toward the pipe, and
 wherein the cap is provided at an end thereof with an inclined support portion that is inclined at an angle that corresponds to an angle at which the latching pieces are inclined so as to support the latching pieces within the grip ring. 
 
     
     
       8. The connecting device according to  claim 1 , further comprising:
 a cap-sealing member disposed in the cap so as to be capable of coming into contact with an outer circumferential surface of the pipe passing through the cap.